const result = window.performance.getEntriesByType('mark')
let fmpTime = 0
for (const entry of result) {
  fmpTime += (entry.startTime + entry.duration)
  console.log(entry)
  console.log(entry.name + ' 执行时间：', entry.startTime + entry.duration)
}
console.log('fmp时间：' + fmpTime)